Finding the Third Proportional to 445,200 and 689,788

Step by Step Solution

1. Step 1: Write the proportion equation
   445,200 : 689,788 = 689,788 : x
2. Step 2: Convert to fraction form
   445,200/689,788 = 689,788/x
3. Step 3: Cross multiply
   445,200x = 689,788 × 689,788
4. Step 4: Simplify right side
   445,200x = 475,807,484,944
5. Step 5: Solve for x
   x = 475,807,484,944/445,200
6. Step 6: Final answer
   x = 1,068,749.97